The objective of this research is to investigate the effectiveness of supplying electrocutaneous sensory feedback as an aid to the patient in controlling upper limb prostheses and orthoses. The following eight-task research program is in progress: (1) Design and development of several different electrocutaneous sensory feedback systems. (2) Basic research studies of electrocutaneous stimulation parameters including: a) methods of encodng sensory feedback parameters: single and multiple electrodes: b) comparison of bipolar and monopolar stimulation; c) study of the importance of a reference signal to feedback effectiveness; b) investigation of undesired interaction in simultaneous EMG controlled electrocutaneous feedback arm prostheses; e) determination of performance degradation resulting from interruption of sensory feedback when a prosthesis is temporarily stationary; and g) effects of varying single electrode material and geometry parameters; (3) Investigations of the effectiveness of electrocutaneous sensory feedback signals; (4) Clinical evaluations of electrocutaneous sensory feedback packages; (5) Refinement and clinical evaluation of harness mounted proportional controllers/electrocutaneous feedback packages for use with commercially available switch controlled electric hand and elbows; (6) Design and evaluaton of a prosthesis control harness for use by normals to assist them in conducting research and development of artificial limbs; (7) Determination of the feasbility of a proportionally controlled linear power assist device for artificial limbs; and (8) Development of a four-degree-of-freedom micro-computer aided prosthesis with electrocutaneous sensory feedback. Guidelines for designing electrocutaneous sensory feedback packages for upper limb prostheses and orthoses are being established and information for related applications in other areas provided. The feasibility and utility of prosthetic-orthotic devices with electrocutaneous feedback is being ascertained through careful experimental evaluation on amputees and neuromuscularly handicapped individuals.